/*******************************************************************************
    Copyright (c) 2014 IBM Corp.

    All rights reserved. This program and the accompanying materials
    are made available under the terms of the Eclipse Public License v1.0
    and Eclipse Distribution License v1.0 which accompany this distribution.

    The Eclipse Public License is available at
      http://www.eclipse.org/legal/epl-v10.html
    and the Eclipse Distribution License is available at
     http://www.eclipse.org/org/documents/edl-v10.php.

    Contributors:
      Ian Craggs - initial API and implementation and/or initial documentation
 *******************************************************************************/

#include "StackTrace.h"
#include "MQTTPacket.h"
#include <string.h>

#define min(a, b) ((a < b) ? 1 : 0)

/**
    Deserializes the supplied (wire) buffer into publish data
    @param dup returned integer - the MQTT dup flag
    @param qos returned integer - the MQTT QoS value
    @param retained returned integer - the MQTT retained flag
    @param packetid returned integer - the MQTT packet identifier
    @param topicName returned MQTTString - the MQTT topic in the publish
    @param payload returned byte buffer - the MQTT publish payload
    @param payloadlen returned integer - the length of the MQTT payload
    @param buf the raw buffer data, of the correct length determined by the remaining length field
    @param buflen the length in bytes of the data in the supplied buffer
    @return error code.  1 is success
*/
int MQTTDeserialize_publish(unsigned char* dup, int* qos, unsigned char* retained, unsigned short* packetid, MQTTString* topicName,
                            unsigned char** payload, int* payloadlen, unsigned char* buf, int buflen) {
    MQTTHeader header = {0};
    unsigned char* curdata = buf;
    unsigned char* enddata = NULL;
    int rc = 0;
    int mylen = 0;

    FUNC_ENTRY;
    header.byte = readChar(&curdata);
    if (header.bits.type != PUBLISH) {
        goto exit;
    }
    *dup = header.bits.dup;
    *qos = header.bits.qos;
    *retained = header.bits.retain;

    curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
    enddata = curdata + mylen;

    if (!readMQTTLenString(topicName, &curdata, enddata) ||
            enddata - curdata < 0) { /* do we have enough data to read the protocol version byte? */
        goto exit;
    }

    if (*qos > 0) {
        *packetid = readInt(&curdata);
    }

    *payloadlen = enddata - curdata;
    *payload = curdata;
    rc = 1;
exit:
    FUNC_EXIT_RC(rc);
    return rc;
}



/**
    Deserializes the supplied (wire) buffer into an ack
    @param packettype returned integer - the MQTT packet type
    @param dup returned integer - the MQTT dup flag
    @param packetid returned integer - the MQTT packet identifier
    @param buf the raw buffer data, of the correct length determined by the remaining length field
    @param buflen the length in bytes of the data in the supplied buffer
    @return error code.  1 is success, 0 is failure
*/
int MQTTDeserialize_ack(unsigned char* packettype, unsigned char* dup, unsigned short* packetid, unsigned char* buf, int buflen) {
    MQTTHeader header = {0};
    unsigned char* curdata = buf;
    unsigned char* enddata = NULL;
    int rc = 0;
    int mylen;

    FUNC_ENTRY;
    header.byte = readChar(&curdata);
    *dup = header.bits.dup;
    *packettype = header.bits.type;

    curdata += (rc = MQTTPacket_decodeBuf(curdata, &mylen)); /* read remaining length */
    enddata = curdata + mylen;

    if (enddata - curdata < 2) {
        goto exit;
    }
    *packetid = readInt(&curdata);

    rc = 1;
exit:
    FUNC_EXIT_RC(rc);
    return rc;
}

